PLATO Character Set (pfcharset)

Utility for accessing PLATO packs and master files.

This is licensed software a copy of the license should have been included in the source tree for this module. You may find a copy of the license here: https://www.gnu.org/licenses/gpl-3.0.en.html

This program operates on PLATO packs and master files. Packs are accessed as DtCyber disk images. Master files (CDC style virtual packs) can be accessed directly (if you have a master file image copy available) or as NOS files contained in a NOS disk image.

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When accessing PLATO file structures, the host pack object needs to be instantiated and then the PlatoFile class may be used to access the underlying structure.

class pfcharset.Charset[source]

Bases: object

Character Set Class used for different types of manipulation.

char_words

Number of words in the charset

Type:: int

char_slots

Dictionary of character entries

Type:: dict

num_blocks: Number of blocks required for the charset

Each char_slot entry is indexed by the ordinal value of the plato character. Slot 0o000 and 0o100 are reserved and always zero. Each character is composed of an 8 bit x 16 bit matrix.

CHAR_HEADER = 16390

char_entry(slot: int) → list[source]

get_blocks() → list[source]

property num_blocks_used: int

property num_slots_used: int

oct_load(charsets_source, charset_name: str) → None[source]: Each entry is two CM Words per line.

set_words(in_words: list)[source]

txt_line_in(line_in: str) → None[source]

txt_line_out(slot: int) → str[source]

pfcharset.block_letters(instring: str = '{PLATO/CYBIS/system}', charset_name: str = 'standard', charsets_source: str = '.\\charsets.tutor.txt', zero: str = ' ', one: str = '#')[source]

Block Letter Banner based on PLATO Charsets.

This function reads the “charsets” lesson dump and selects any of the in-built character sets standard, rounded, orange, etc. and enables a string of text to be rendered in a 16-row raster.

Input interprets the standard ASCII characters but accesses the “meta” characters using the ‘backtick’ ( ` ) character. In this way, rendering the Divide symbol can be accomplished by typing `/ and Micro-A can be accessed by typing `A.

The _c2d translation table represents the various character states wherein a backtick causes a shift to the next series.

The result of the parser is a list of indexes into the character set which is then rasterized and pivoted into a left-to-right horizontal raster.